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(No Mode l.) HLDE W. SAWYER.

HEATING APPARATUS.

No. 584,749, Patented June 15, 1897.

WITNESSES- NlTED STATES PATENT FFICE.

HOlVARD DE \VOLFE SAWVYER, OF REVERE, MASSACHUSETTS, ASSIGNOR TO THENEMO HEATER COMPANY, OF PORTLAND, MAINE, AND BOSTON,

MASSACHUSETTS HEATING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 584,749, dated June 15,1897.

Application filed March 12, 1896. Serial No, 582,862. (No model.)

To all whom it may concern.-

Be it known that I, HOWARD DE WOLFE SAWYER, of Revere, in the county ofSuffolk and State of Massachusetts, have invented certain new and usefulImprovements in Heating Apparatus, of which the following, taken inconnection with the accompanying drawings, is a specification.

The object of this invention is to provide improved forms of heatingapparatus, especially for household or domestic purposes, such ascooking-stoves, parlor-stoves, open grates, &c., in all of which adownward draft is maintained through the fuel resting upon a tubulargrate through which a constant circulation of water is kept up, suchwater rising as it becomes heated and serving to heat other rooms towhich it may be conducted, after which it returns or may return to thelower part of the heater to repeat its course.

The construction peculiar to my present invention embraces a fire-pothaving an inclined water-grate and reversely-inclined supplypipescommunicating with and diverging from a water-box or vertical table atthe back or inner end of the fire-box, in combination with a frontwater-wall made in two separate sections, one above the other, connectedfor water circulation only through said supplypipes, water-box, andgrate-tubes, the supplypipes rising obliquely from the upper part of thelower section of said wall and the grate tubes rising obliquely to thelower part of its upper section, so that elfective circulation is at alltimes maintained. By a door or doors closing the open space between thesections of this front water-wall access is had between said pipes andtubes to the under surface of the grate, which slopes downwardly awayfrom said door, giving opportunity to rake the fire, if desired. A micaor tough-glass panel may be inserted in this door to make the interiorvisible, and minute air-inlets may admit jets of oxygen to thegasflamee. An ashdoor at bottom of the front wall permits removal ofashes when required. A fire-brick back,side walls,and bottom flue areprovided. The draft-inlet is above the grate, through griddle-holes inthe top, or by a broiler-opening at the upper edge of the front wall,and the descending caloric current passes in an open flue entirelyaround the oven in cookingstoves, giving with a moderate fire the mosteffective results. In heaters without ovens the current will take a moredirect course upwardly after passing under the fire'brick or other back.

I propose to build heaters complete according to my present invention orto furnish the water-front sections and the grate, supplypipes, andwater-box, suitably arranged for insertion in ordinary stoves, in placeof the usual front and fire-box. The water-supply will enter the bottomof the lower section of the water-front and the flow will be from thetop of its upper section to a tank for domestic purposes or to radiatorsfor return to the'stove and repeated circulation, or to both tank andradiators.

The. drawings show in Figure 1 a vertical longitudinal section through acooking-stove embodying my invention. Fig. 2 is a transverse verticalsection on the irregular line 2 2 of Fig. l.

A represents the side wall, and B the firebrick back, of the fire-pot. Ois the oven in rear thereof, and D the caloric passage beneath andaround the oven. Griddle-holes in the top of the fire-pot and furnishedwith covers E serve to admit fuel and constitute draft-openings. Whenthese holes are closed by the covers or by kettles, the draft is throughthe broiler-opening F at top of the front, furnished with a suitabledoor. Other griddle-holes are formed in the stovetop over the oven.

G G are the two independent sections of the hollow water-containingfront wall, arranged verticallyand at some distance apart, so as toafford access by sliding or swinging doors 1-1 to the space betweenthem. The grate J extends obliquely downward fromthe lower part of theupper section G of this water-wall. It is composed of parallelcloselyset water-tubes screwed at front into said section G and at therear or lower end into the transverse water-box K, which lies nearly incontact with the side of the oven or of the back 13, allowance beingmade for expansion when heated. The lower section G is connected at itsupper portion with the water-box K by two or more enlarged water-supplypipes L, which run obliquely to facilitate Water circulation. It will beseen that the heated water rising from the lower section G' must passthrough the supply-pipes L, the waterboX K, and the grate-tubes J, andhence that when in use the water necessarily circulates through theseparts and cannot short-circuit directly upward, as is possible underother constructions. The tubular grate and supply-pipes are thereforeprotected from the intensity of the heat by the constant flow of waterthrough them.

The door H, opening between the grate and water-supply tubes, is keptclosed except when it maybe necessary to rake the fire, the undersurface of the grate being readily aecessible when such dooris open. Oneor more panels of mica or tough glass M may occupy its central portion,around which a series of small perforations 1.) admit jets of air tomingle with the gas-flames shooting downward through the grate, thuspromoting combustion without destroying the downward draft.

I claim as my invention" 1. In a downdraft heating apparatus, thefire-pot having a hollow, water-containing front made in two independentsections, one above the other, in combination with the tubularwater-grate extending obliquely downward from the lower part of theupper section, the Water-supply pipes beneath the grate, inclined in theopposite direction and entering the upper part of the lower section, andwith the water-box at the inner or back end of the fire-box into whichthe converging supplypipes and grate-tubes enter, substantially as setforth.

2. In a downdraft heating apparatus, the front wall formed of twoindependentwatercontaining sections and a door closing the open spacebetween them, with a draft-inlet above and an ash-door below saidsections, in combination with a water'box at the rear end of thefire-box and with reversely-inclined grate-tubes and supply-pipesconnecting respectively the upper and lower sections to said water-box,whereby circulation is en forced through the several parts,substantially as set forth.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, on this 20th day of February, A.D. 1896.

HOWARD DE WOLFE SAWlER.

Vitnesses:

A. H. SPENCER, D. W. WoRMWoon.

